A New Approach to Nonlinear Modelling and Simulation of MESFETs and MODFETs

A new method for the derivation of a FET-equivalent-circuit for large- and small-signal applications is presented. The model consists of nine bias-dependent intrinsic elements additionally eight linear extrinsic elements. All circuit-elements are determined from measured DC- and scattering-parameters with an analytical method at any bias-condition. The nonlinear behaviour of the intrinsic elements are expressed using two-dimensional spline-functions. The large-signal simulation considers all nonlinear intrinsic elements including the Schottky-diodes and the gate-drain avalanche breakdown.